This invention relates to fishing lines, and more particularly to a buoyant fishing line particularly adapted for use in fly fishing.
In fly fishing, a small substantially weightless hooked lure, which resembles a fly or other insect, is cast upon the water. Normally, the fly or artifical lure is attached to a monofilament "leader" which is virtually transparent in the water and which sinks just below the surface of the water, while the fly or artifical lure remains on the water surface or just below same. Attached to this "leader" is the line, which is typically cast with the particular types of weight rods used for fly fishing.
In casting the fly or artifical lure, since both are extremely light, substantially all the propelling force and momentum for the lure must necessarily come from the line itself. However, the use of a "heavy" line is prohibited since the line must be capable of floating on the surface of the water in order that the lure or fly will similarly float thereon. Therefore, the line cannot have a specific gravity of above approximately 1.15 or the surface tension of the water will not be sufficient to keep the line afloat.
A fly fishing line of high quality should be stiff enough to throw its own weight in a substantially straight line from the end of the fly rod to the target when casting; it must be sufficiently flexible to afford good "throwing" and "laying" characteristics; it should float; it should be sufficiently hard-surfaced such that it will "shoot" well, i.e., easily pass through the guides of the fly rod; it should have a sufficiently tough surface that it may not become cracked and broken during use; it should have sufficiently high tensile strength and stretch without permanent elongation; it should be resistant to temperature changes, i.e., be stable at 0.degree. C. and 50.degree. C. without becoming brittle or sticky; it should have a life-long floating characteristic not requiring frequent dressing, if any; it should be water-repellent such that it need not be dried after use; it should be resilient after being creased or sharply bent, i.e., not subject to "elbowing"; and the tip portion thereof should be small so as to be less visible to the fish.
Prior art fly fishing lines have been disclosed which attempt to meet the foregoing criteria. One such disclosure is U.S. Pat. No. 3,043,045, where there is disclosed a fly line including a core member of substantially uniform diameter made of, for example, a braided nylon filament, an adhesive priming coating over the core, and a tapered plastisol coating of, for example, polyvinyl chloride having embedded therein a controlled quantity of preformed bubbles of microscopic size, such as hollow microspheroids or microballoons which impart a controlled degree of buoyancy to the line.
U.S. Pat. No. 3,830,009 and United Kingdom Pat. No. 1,369,256 disclose the use of an inert gas incorporated into the fly line during the extrusion thereof to form a somewhat foamed internal core. U.S. Pat. Nos. 3,849,929 and 3,936,335 disclose a foamed core surrounded by a filamentous line to provide improved buoyancy to the fly line. U.S. Pat. No. 3,914,480 discloses an improved plastisol coating for the surface of fly lines to impart desired characteristics thereto.
It has now been found that by compounding a hereinafter defined fluorochemical into an only preferred composition useful as the fly line plastic surface coating, the fly line has better castability, better shootability, better floatability, and can be picked up easier, because water will not wet same as readily as prior art fly lines.